Local authorities in a remote town in northern Guangdong are being accused of covering up the severity of pollution in the area. Residents reject the official tally of only 18 severe cases of lead poisoning and say hundreds of children are suffering.

In May, word spread online that many children in Xingzi township, Lianzhou , had tested positive for lead contamination, believed to be caused by pollutants from a local government-supported power station.

That triggered repeated protests against Xingzi officials by hundreds of villagers.

Eager to quell the public's anger, authorities shut the Lianzhou Power Plant in early June and said 18 children had been found with excessive levels of lead in their bodies and had been treated at hospital, but the figure has not been updated.

However, public doubts about the government's official tally were again raised yesterday after a report by China Business News revealed that on a single street, 196 children tested positive for excessive lead, based on normal levels of zero to 100mg per litre of blood. And 95 samples exceeded 450mg per litre, according to the newspaper.

A level of more than 200mg is considered hazardous, and medical studies indicate that such concentrations can impair children's mental health and affect their growth.

The plant used to be coal-fired, producing large amounts of dust that residents said contaminated rivers and groundwater. Lead pollution is a rare result of power plants, but the situation in Lianzhou is unique because coal from the area has high lead content, according to the report.

Li Fuzhong , who runs a bottled-water and beverage shop on Dongsheng Road in the township, told the South China Morning Post that more than 90 per cent of the children he knew - including two of his grandchildren and neighbours in his community - had been poisoned.

"My nine-year-old granddaughter was tested in June and found with a level of 299mg, while other children, almost every child I know, had a level ranging from 100 to 600mg per litre," Li said, adding that the local government offered free examinations for children under 15.

He Jianbo , from Xiaochong village in the town, ridiculed officials for saying the total number of sick children was only 18. "The plant is seven kilometres from our village," He said. "There are about 3,000 people in my village. Almost every family there has kids suffering from [lead] poisoning. That doesn't include people living just a few hundred metres from the plant."

Since the factory was built in 2002, villagers have complained about the air being foul, with adults coughing and parents saying that their children's growth was stunted, that they could not sleep at night and could not concentrate at school.

"The clothes we wore were covered in grey that couldn't be washed out. But we didn't know the result would be so horrible," He said.

In the three months since the poisoning was revealed, villagers said they had received medicine only twice - mostly calcium and vitamin tablets, and some milk.

The power plant's operations have been suspended, but villagers are worried it may resume production when all the publicity dies down.

This article appeared in the South China Morning Post print edition as Villagers' fury at children's lead poisoning